fn func(mut t: i32) {
    let v1 = 23 + t;
    let v2 = "xxx";
    let p1 = &v1;
    let p2 = &v2;
    println!("v1: {}", *p1);
    unsafe {
        println!("unsafe v2: {}", *p2);
    }
}

fn main() {
    let t = 1;
    func(t);
}
